Dynamic ultrasonography for optimizing treatment position in superior mesenteric artery syndrome: Two case reports and review of literature

Abstract

BACKGROUND Superior mesenteric artery (SMA) syndrome is a rare cause of duodenal obstruction by extrinsic compression between the SMA and the aorta (SMA-Ao). Although the left lateral recumbent position is considered effective in the treatment of SMA syndrome, individual variations in the optimal patient position have been noted. In this report, we present two elderly cases of SMA syndrome that exhibited rapid recovery due to ultrasonographic dynamic evaluation of the optimal position for each patient. CASE SUMMARY Case 1: A 90-year-old man with nausea and vomiting. Following diagnosis of SMA syndrome by computed tomography (CT), ultrasonography (US) revealed the SMA-Ao distance in the supine position (4 mm), which slightly improved in the lateral position (5.7–7.0 mm) without the passage of duodenal contents. However, in the sitting position, the SMA-Ao distance was increased to 15 mm accompanied by improved content passage. Additionally, US indicated enhanced passage upon abdominal massage on the right side. By day 2, the patient could eat comfortably with the optimal position and massage. Case 2: An 87-year-old woman with vomiting. After the diagnosis of SMA syndrome and aspiration pneumonia by CT, dynamic US confirmed the optimal position (SMA-Ao distance was improved to 7 mm in forward-bent position, whereas it remained at 5 mm in the supine position). By day 7 when her pneumonia recovered, she could eat with the optimal position. CONCLUSION The optimal position for SMA syndrome varies among individuals. Dynamic US appears to be a valuable tool in improving patient outcomes.